QT dispersion is not associated with sudden cardiac death or mortality in heart transplant recipients.
BACKGROUND
Sudden cardiac death (SCD) has been shown to be a significant cause of death after heart transplantation. QT dispersion (QTd) is associated with SCD in several high-risk populations. We hypothesized that QTd would predict mortality and SCD in heart transplantation patients.


METHODS
We examined the clinical charts and most recent electrocardiograms (ECGs) for patients who received heart transplants at Stanford University Medical Center during the period 1981-1995. QTd was measured with all 12 leads and the precordial leads. Analysis was performed by a single reader blinded to patient outcomes.


RESULTS
A total of 346 patients who had undergone transplantation had available ECGs and known outcomes; 155 of these patients died, and 42 of these deaths were attributed to SCD. The 12-lead mean QTd was not significantly different between outcome groups: patients who survived had a 12-lead mean QTd of 58 +/- 29 milliseconds and those who died had a 12-lead mean QTd of 61 +/- 32 milliseconds (P = .57). Patients who died from SCD had a 12-lead mean QTd of 57 +/- 31 milliseconds (P = .40), and those who died of other causes had a 12-lead mean QTd of 59 +/- 34 milliseconds (P = .36 vs those who died of SCD). Similarly, the precordial-lead mean QTd did not differ significantly between the different outcome groups.


CONCLUSIONS
We found no correlation between QTd and SCD or mortality in heart transplant recipients. Until additional studies prove a positive association, QTd should not be used as a prognostic marker in these patients.
Marcus
Gregory M
GM
Cardiac Electrophysiology, University of California, San Francisco, CA, USA. marcusg@medicine.ucsf.edu
Hoang
Khanh L
KL
Hunt
Sharon A
SA
Chun
Sung H
SH
Lee
Byron K
BK
D001145:Arrhythmias, Cardiac / Q000175:diagnosis* / Q000401:mortality*; D002140:California / Q000453:epidemiology; D016757:Death, Sudden, Cardiac / Q000453:epidemiology*; D004562:Electrocardiography / Q000379:methods / Q000706:statistics & numerical data*; D005260:Female; D016027:Heart Transplantation / Q000401:mortality*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012680:Sensitivity and Specificity; D016019:Survival Analysis; D015996:Survival Rate